The open access architecture of the Internet allows a user to communicate with other users and to access a global array of networked resources. The open access nature of the Internet can however, be a liability. Unwanted data traffic from malicious sites can degrade network and user operations. Examples of unwanted data traffic include: e-mail spam, phishing attacks or Distributed Denial-of-Service (DDoS) attacks.
One approach to reducing unwanted data traffic is to create a “blacklist” of malicious Internet sites and to filter data traffic based on its origin. This approach is often referred to as “blacklist filtering”. Traffic originating from sites that are members of the blacklist could be subject to mitigating actions. Mitigation actions could include blocking or not transmitting data packets, reducing the rate at which data packets are transmitted or diverting the data packets for deep packet inspection, for example.